Logic gates, pull up/down resistor

[Arouse1973]

yes yes it is.

I just wondered why you had that little red and black link. Are all those separate blocks going across the breadboard joined together? It's been 25 years since I have used that sort of thing.
Adam

 

[Luke Vassallo]

I will try this tomorrow and let you know how it works cause in 6hrs I have to wake up for school. Thanks a lof for you help. really appreciate

 

[Arouse1973]

Is the top IC defiantly grounded (connected to zero Volts) Can you take another picture showing the top IC?

 

[Luke Vassallo]

that is because they are separated in two. if I just connect the upper ones only I won't have any current in the lower ones then

 

[Arouse1973]

I will try this tomorrow and let you know how it works cause in 6hrs I have to wake up for school. Thanks a lof for you help. really appreciate

OK, good night

 

[Arouse1973]

Your circuit could also be oscillating which is why you are measuring 2.5 Volts.
Adam

 

[Arouse1973]

that is because they are separated in two. if I just connect the upper ones only I won't have any current in the lower ones then

Ok I see it now, thanks
Adam

 

[Arouse1973]

there are also some images of the build. I was wondering could I have damaged the chip since it is outputting a 0.8v at the ouput even with just vdd and gnd connected to it

Your job for tomorrow is to sort out the wiring , it's quite messy and those long wires might not be helping matters. Make all connections as short as possible. Move the top IC down with the others if you can. This will reduce the length of the wires.
Adam

 

[Luke Vassallo]

Hi Gryd3 and Adam,

sorry for the late reply, but I was overloaded with schoolwork and more assignments (a 3 stage amplifier now), and last week I got an arduino and wasted quite a lot of time experimenting with it. I did as you suggested and kept the workspace a bit neater. However the problems I encountered where really trivial. Sometimes I left an IC without power or a missing cable and I even rush a bit and wire the wrong inputs.

But the main problem and it is a funny one is, I thought that for the quad 2 input and/or gates and the inverters, they are wired always the same(i.e. if pins 1,2 are inputs and pin 3 is output, then pins4,5 are inputs and pin 6 is output again). This messed up the entire system and I I had even some voltage on the rails when the switch was off.

Well once I figured that out, the system worked perfectly.

I appreciate the help and again i'm sorry for the late reply